Hydrates in LPG Cargoes
: Witherby Seamanship International Ltd
This publication is a technical review of the processes and procedures commonly found in production, storage and transportation of LPG cargoes. It shows how it is possible for water to enter or remain in the cargo, leading to hydrate formation. The guide’s recommendations are aimed at the elimination of hydrate formation.
It became apparent that hydrates were occasionally and unpredictably appearing in the cargo systems of refrigerated LPG carriers. This resulted in damage to pumps and other plant machinery being damaged, as well as interference to cargo handling. While the procedures used to produce LPG and its handling on ship and shore includes minimising the water content in the product, little
information has been gathered that specifically deals with hydrates forming in commercially dry refrigerated LPG. As a result, a review of the processes and procedures commonly used in production, storage and transportation was required to identify how water can enter or remain within the cargo.
The review was conducted by Mr R C Gray of the Technology Department of British Shipbuilders. His findings and recommendations for eliminating hydrates can be found in this publication.
This document provides a unique collation of data on this subject, some deductions and imaginative recommendations based on the data. The book was originally published for the benefit of SIGTTO members but has since been made generally available due to its usefulness in the liquefied gas industry.